Piston and cylinder construction



Nov. 28, 1944. J MCLINTOCK PISTON ANIS CYLINDER CONSTRUCTION Filed June 11,1943

lizzvezz/iaz yfiar/iock Patented Nov. 28, 1944 John McLintock,

Mount Vernon, Glasgow, Scotland Application June 11, 1943, Serial No. 490,538 In Great Britain July 27, 1942 1 Claim, .(Cl. 309-4) This invention has reference to piston and cylinder construction wherein a piston reciprocates within a cylinder.

The present invention has for its object to provide improvements whereby wear of the cylinder wall of a reciprocating engine, including air compressors, will be substantially eliminated.

On the annexed sheet of drawing is illustrated byway of example a preferred embodiment of the invention wherein:

Figure 1 is a sectional elevation of part of the cylinder and piston located therein and Figure 2 is a section on the line 22.

In the drawing a designates the cylinder of an engine, compressor or the like. The wall of the cylinder is provided with two diametrically pposite longitudinally or axially'extending recesses 1212. Each recess may be the same length or substantially the same length as the cylinder, while the breadth thereof may be as found con venient, e. g. it may be about of the circumference of the cylinder.

The depth of each recess may be somewhat more than the thickness ofthe cylinder wall.

The piston c is of usual construction except that bearing shoes at and d are secured thereto on diametrically opposite sides, the said shoes fitting within the said recesses 12,1), and being of such size that they make a good working fit therein. a

The bearing shoes are at least the length of the piston and bear throughout their length on all faces of the recesses into which they fit.

The inner face of eachshoe is provided with a number of circumferentially extending recesses of such size and so positioned that thetusual split piston rings e carried by the piston are snugly accommodated therein, the shoes being thereby prevented from axial movement relative to the piston.

In introducing the piston together with the bearing shoes into the cylinder it is preferable first to introduce thin liners to bear against the back of the said recesses and whenthe piston and bearing shoes are introduced said liners are then withdrawn.

The piston rings 6 in addition to preventing a relative axial movement of the shoes d and piston 0 have the effect of forcing the shoes outwardly'so that the piston is held centrally in its cylinder and the wear and tear is taken up not by the piston and the piston rings but by the said bearing shoes which of course can be readily renewed if found necessary; a

By such improvements there is little or n wear in the piston and piston rings so that loss ied as found desirable, e. g.in certain instances by the escape of fluid between the piston an cylinder is substantially avoided.

If desired, the number of longitudinally ex-,

tending recesses and bearing shoes may be var- It will beunderstood that the piston may be secured to the piston rod by means of a gudgeon same to the piston.

pin. I claim:

A piston and cylinder assembly embodying a 7 cylinder having at least one longitudinally or axially extending recess in the cylindrical wall thereof, a piston with piston rings working in said cylinder, bearing shoes, corresponding in number to the-number of recesses in the cylindrical wall, carried by said piston and each fitting into a recess, each shoe extending at least the length of the piston and bearing throughout its length on all faces of the recess into which it fits, and each having circumferential recesses into which the JOHN MCLINTTOCK.

Or, if desired,

piston rings lit to lock 

